Sedentary lifestyle trumps smoking for heart disease risks in some

For women age 30 and older, being a couch potato could be more hazardous to heart health than smoking or carrying extra weight, say researchers shining a spotlight on the need for physical activity programs at all ages.

Researchers in Australia weighed how smoking, high blood pressure, physical inactivity and high body mass index contribute to the likelihood of developing heart disease across the lifespan of females.

They analyzed data from more than 32,000 women participating in the Australian Longitudinal Study on Women's Health that’s been tracking the health of those born in the 1920s, 1940s, 1970s and since 1996.

"The data show that of these four risk factors, physical inactivity is the most important contributor to heart disease at the population level," study author Prof. Wendy Brown of the Centre for Research on Exercise, Physical Activity and Health at the University of Queensland said in an email.

"At present, most of the focus is on obesity. These data clearly show that inactivity deserves greater emphasis."

In Thursday’s issue of the British Journal of Sports Medicine, Brown and her team estimated that in young women up to age 30, smoking is comparatively more important than other risk factors for heart disease.

That changes when women reach their 30s as they tend to quit smoking when they become mothers, Brown said.

The researchers estimate that if every woman between the ages of 30 and 90 were able to reach the recommended level of 150 minutes of at least moderate intensity physical activity — like playing golf or recreational swimming or gardening — then the lives of more than 2,000 middle-aged and older women could be saved each year in Australia alone.

In Canada, a 2004 study also suggested that a large proportion of heart disease in Canadian adults is directly attributable to low physical activity levels, said study author Prof. Ian Janssen. He holds the Canada Research Chair in physical activity and obesity at Queen’s University in Kingston, Ont.

The Australian researchers concluded that national programs to promote physical activity deserve a higher public health priority for women of all ages than they have now.

Physical activity should be a focus for public health for children in school right up to seniors, said Paula Harvey, director of the cardiovascular research program at Women’s College Hospital in Toronto.

"When I am counselling patients, which I do frequently because I see patients both with cardiovascular disease and with hypertension, I will tell them if they want to know what I think is the tonic of youth, good health and good cardiovascular health, it is exercise," Harvey said.

Harvey’s own research on women walking comfortably on a treadmill for 45 minutes showed benefits on blood pressure and the health of blood vessel cells, which are important in reducing heart attack risk. The blood pressure effects are immediate, easy to measure and can be a gratifying motivator to get women moving, she said.

In Canada, women are less likely to take up exercise and stick with it and they’re more likely to become inactive as they get older, Harvey said, quickly adding that men aren’t doing a great job on the physical activity front either.

"This sedentary lifestyle is a real problem," Harvey said. "I like to counsel women that walking is a fantastic, underrated exercise. All you need to do is put your shoes on and make sure you’ve got the correct layers."

Walking around the block is low impact, helps the bones, heart and psyche and at the same time can foster good relationships with neighbours, noted Harvey.

Growing up in Australia herself, Harvey said she enjoyed playing organized sports. Now she loves to run as many days as possible as well as hike, garden and ski.

The study was funded by the Australian government.